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A257722 Hexagonal numbers (A000384) that are the sum of eleven consecutive hexagonal numbers. 4
946, 1540, 13695, 1151403, 18773128, 1590903028, 25941294753, 2198372138061, 20904988593016, 35846699817610, 340877159895525, 28887334308843153, 471037447946228878, 39917653136343078778, 650898046192856866503, 55159780922590010984691 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Colin Barker, Table of n, a(n) for n = 1..767

Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,0,0,0,25091193602,-25091193602,0,0,0,0,0,0,-1,1).

FORMULA

G.f.: -11*x*(21*x^16 +252*x^15 +4025*x^14 +359100*x^13 +5562025*x^12 +496218492*x^11 +4272895055*x^10 +3412929546*x^9 -457241153867*x^8 +197493713028*x^7 +2213671975*x^6 +142920900*x^5 +1601975*x^4 +103428*x^3 +1105*x^2 +54*x +86) / ((x -1)*(x^2 -20*x +1)*(x^2 +20*x +1)*(x^4 +398*x^2 +1)*(x^8 +158402*x^4 +1)).

EXAMPLE

946 is in the sequence because H(22) = 946 = 1 + 6 + 15 + 28 + 45 + 66 + 91 + 120 + 153 + 190 + 231 = H(1)+...+H(11).

PROG

(PARI) Vec(-11*x*(21*x^16 +252*x^15 +4025*x^14 +359100*x^13 +5562025*x^12 +496218492*x^11 +4272895055*x^10 +3412929546*x^9 -457241153867*x^8 +197493713028*x^7 +2213671975*x^6 +142920900*x^5 +1601975*x^4 +103428*x^3 +1105*x^2 +54*x +86) / ((x -1)*(x^2 -20*x +1)*(x^2 +20*x +1)*(x^4 +398*x^2 +1)*(x^8 +158402*x^4 +1)) + O(x^100))

CROSSREFS

Cf. A257721, A257723, A257724.

Sequence in context: A133353 A322252 A119240 * A093247 A248785 A199924

Adjacent sequences:  A257719 A257720 A257721 * A257723 A257724 A257725

KEYWORD

nonn,easy

AUTHOR

Colin Barker, May 06 2015

STATUS

approved

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Last modified May 13 04:09 EDT 2021. Contains 343836 sequences. (Running on oeis4.)